1. Field of the Invention
The present invention generally relates to an ink jet device and a method for operating the ink jet device.
2. Description of Related Art
With recent advances in personal computers, especially portable personal computers, the demand tends to arise for liquid crystal displays, especially color liquid crystal displays. However, in order to further popularize the use of liquid crystal displays, a reduction in cost must be achieved. Especially, it is required to reduce the cost of a color filter, which occupies a large proportion of the total cost of the liquid crystal display (LCD).
Various methods have been tried to satisfy the required characteristics of the color filters while meeting the above requirements. Ink jet method is one of the methods. In the ink jet method, RGB (red, green, and blue) color layer is formed by jetting ink into spaces formed on a substrate using an ink jet device. RGB color layer can be formed at once and the efficiency of material is increased, thus decreasing the cost of the color filter. Therefore, ink jet devices are becoming more popular in manufacturing of color filters.
In the ink jet device, a pressure difference between a print head and an ink tank is kept constant so as to maintain a good printing performance. However, the print head moves upward and downward in a vertical direction in printing, for example, returning to a home position along the vertical direction. In a typical ink jet device, the pressure difference varies due to a change of a height of the print head, thus causing ink leakage from the print head, or causing the print head to suck in air. In this case, the printing performance of the ink jet device is weakened, and maintenance time for the ink jet device is increased.
It is therefore desirable to find a new ink jet device and a new method, which can overcome the above mentioned problems.